But the PC is still the top dog when it comes to gadgets. In U.S. homes with Internet access, 93 percent had PCs.

That number isn’t budging much, though it’s nothing to sneeze at.

Smartphones and tablets each are in 57 percent and 53 percent of U.S. homes, respectively. Separately, the devices significantly lag behind PCs, but combined, there are more homes with mobile devices than desktops or laptops.

Tablets alone have seen a huge surge in the last three months. From the last quarter of 2012 to the first quarter of this year, tablet penetration jumped from 35 percent to 53 percent.

The great migration

The increases are higher than they normally would be because of holiday sales, says John Buffone, director of devices for NPD’s Connected Intelligence division. First-time tablet buyers drove the increase. Buffone expects more basic cell phone users to switch to smartphones in the next year or two, continuing the momentum.

We aren’t choosing one device over another (like turning to a tablet and getting rid of the family PC), but instead stockpiling new gadgets as they’re released. The average number of Internet-connected devices per household increased in the first three months of the year from 5.3 to 5.7.

The average home has 2.4 desktops or laptops, which has remained steady.

“What we are seeing is more shifts in usage,” Buffone says. “Thirty-seven percent of PC users migrated some activity to their mobile device.”

Both tablet and smartphone owners list Internet browsing and Facebook surfing as the top two activities they moved from PC to mobile devices, according to a February report from NPD Group.

Despite the rise of mobile, Buffone said desktops and laptops are still by far the most popular devices in U.S. households, and that likely won’t change anytime soon.